Display panel and display device

ABSTRACT

Provided are a display panel and display device. The display panel includes a driver circuit comprising a shift register that is N-stage cascaded, wherein N is a number greater than or equal to 2; where the shift register comprises: a third control unit configured to receive a first voltage signal and generate an output signal in response to a signal of a third node, or receive a second voltage signal and generate an output signal in response to a signal of a second node; and a fourth control unit comprising a first capacitor, a first transistor and a second transistor, where a second plate of the first capacitor is connected to a drain of the first transistor, a source of the second transistor is connected to a first node, and a drain of the second transistor is connected to the third node.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This is a continuation application of U.S. patent application Ser. No.17/878,213, filed on Aug. 1, 2022, which claims priority to ChinesePatent Application No. 202011621871.7 filed Dec. 31, 2020, thedisclosures of which are incorporated herein by reference in theirentirety.

TECHNICAL FIELD

The present disclosure relates to the field of display panel and, inparticular, to a display panel and a display device.

BACKGROUND

In the field of display, the shift register is often used in order toimplement scanning display or other functions. However, when the shiftregister operates, the voltage of the control node inside the shiftregister inevitably has a threshold loss. Therefore, the transistor inthe corresponding shift register cannot sufficiently be on so that thelevel of the output terminal of the shift register cannot reach thetarget voltage, causing the tailing phenomenon to occur and affectingthe display effect.

When the output signal of the p-type metal oxide semiconductor (PMOS)transistor in the shift register is transitioned from a high level to alow level, the potential of the gate of the PMOS transistor is potentialVgl, and the potential of the source of the PMOS transistor is alsopotential Vgl, that is, the potential of both the gate and the source ofthe PMOS transistor are potential Vgl, and the PMOS transistor operatesin an unsaturated state, causing the voltage of the drain output to be|Vgl|−|Vth|, where Vth is the threshold voltage of the PMOS transistor.

Since the voltage of the drain output of the PMOS transistor does notreach the effect of the predetermined output Vgl, there is the tailingphenomenon when the output pulse signal of the existing shift registertransitions from a high level to a low level.

SUMMARY

The present disclosure provides a display panel and a display device.

In a first aspect, the embodiments of the present disclosure provide adisplay panel. The display panel includes a driver circuit.

The driver circuit includes an N-stage cascaded shift register, where Nis greater than or equal to 2.

The shift register includes a first control unit, a second control unit,a third control unit, and a fourth control unit.

The first control unit is configured to receive an input signal andcontrol a signal of a first node in response to a first clock signal.

The second control unit is configured to receive a first voltage signaland a second voltage signal and control a signal of a second node inresponse to the signal of the first node, the first clock signal, and asecond clock signal.

The third control unit is configured to receive the first voltage signaland generate an output signal in response to a signal of a third node,or receive the second voltage signal and generate an output signal inresponse to the signal of the second node, where the third node isconnected to the first node, the first voltage signal is a low levelsignal, and the second voltage signal is a high level signal.

The fourth control unit is connected to the third node and configured tocontrol a potential of the third node to be a first low level signal forat least a first time period within time when the first node is a lowlevel signal, where the potential of the first low level signal is lowerthan the potential of the first voltage signal.

In a second aspect, the embodiments of the present disclosure furtherprovide a display device including the display panel described in thefirst aspect.

The display panel provided by the embodiments of the present disclosureincludes a driver circuit, where the driver circuit includes an N-stagecascaded shift register which includes a first control unit, a secondcontrol unit, a third control unit, and a fourth control unit, where thethird control unit is configured to receive the first voltage signal andgenerate the output signal in response to the signal of a third node, orreceive the second voltage signal and generate the output signal inresponse to the signal of the second node. Since the fourth control unitis connected to the third node and can control the potential of thethird node to be the potential of the first low level signal for atleast the first time period within time when the first node is the lowlevel signal, and the potential of the first low level signal is lowerthan the potential of the first voltage signal, that is, the potentialof the third node is lower than the potential of the first voltagesignal so that the transistor in the third control unit rapidlyapproaches the saturation state and outputs the first voltage signal,thereby avoiding the tailing problem.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a structural diagram of a shift register in the related art;

FIG. 2 is a timing diagram of the shift register shown in FIG. 1 ;

FIG. 3 is a structural diagram of a shift register of a display panelaccording to an embodiment of the present disclosure;

FIG. 4 is a structural diagram of another shift register of a displaypanel according to an embodiment of the present disclosure;

FIG. 5 is a structural diagram of another shift register of a displaypanel according to an embodiment of the present disclosure;

FIG. 6 is a structural diagram of another shift register of a displaypanel according to an embodiment of the present disclosure;

FIG. 7 is a structural diagram of another shift register of a displaypanel according to an embodiment of the present disclosure;

FIG. 8 is a structural diagram of another shift register of a displaypanel according to an embodiment of the present disclosure;

FIG. 9 is a structural diagram of another shift register of a displaypanel according to an embodiment of the present disclosure;

FIG. 10 is a structural diagram of another shift register of a displaypanel according to an embodiment of the present disclosure;

FIG. 11 is a structural diagram of another shift register of a displaypanel according to an embodiment of the present disclosure;

FIG. 12 is a structural diagram of another shift register of a displaypanel according to an embodiment of the present disclosure;

FIG. 13 is a structural diagram of another shift register of a displaypanel according to an embodiment of the present disclosure;

FIG. 14 is a timing diagram of the circuit structure shown in FIG. 13 ;

FIG. 15 is a structural diagram of another shift register of a displaypanel according to an embodiment of the present disclosure;

FIG. 16 is a timing diagram of the circuit structure shown in FIG. 15 ;

FIG. 17 is a structural diagram of another shift register of a displaypanel according to an embodiment of the present disclosure;

FIG. 18 is a timing diagram of the circuit structure shown in FIG. 17 ;

FIG. 19 is a structural diagram of another shift register of a displaypanel according to an embodiment of the present disclosure;

FIG. 20 is a timing diagram of the circuit structure shown in FIG. 19 ;

FIG. 21 is a structural diagram of another shift register of a displaypanel according to an embodiment of the present disclosure;

FIG. 22 is a timing diagram of the circuit structure shown in FIG. 21 ;

FIG. 23 is a structural diagram of another shift register of a displaypanel according to an embodiment of the present disclosure;

FIG. 24 is a timing diagram of the circuit structure shown in FIG. 23 ;

FIG. 25 is a structural diagram of another shift register of a displaypanel according to an embodiment of the present disclosure; and

FIG. 26 is a structural diagram of a display device according to anembodiment of the present disclosure.

DETAILED DESCRIPTION

Hereinafter the present disclosure will be further described in detailin conjunction with drawings and embodiments. It is to be understoodthat the embodiments set forth herein are intended to explain thepresent disclosure and not to limit the present disclosure.Additionally, it is to be noted that for ease of description, merelypart, not all, of the structures related to the present disclosure areillustrated in the drawings.

FIG. 1 is a structural diagram of a shift register in the related art,and FIG. 2 is a timing diagram of the shift register shown in FIG. 1 .With reference to FIGS. 1 and 2 , when the shift register needs totransition from a high level to a low level, the transistor P1 needs tobe off, and the transistor P2 needs to be on. In this case, thepotential of the gate of the transistor P2 is potential Vgl, and thepotential of the source of the transistor P2 is also potential Vgl, thatis, the potential of both the gate and the source of the transistor P2is potential Vgl, and the transistor P2 operates in an unsaturatedstate, causing the voltage of the drain output of the transistor P2 tobe |Vgl|−|Vth|, where Vth is the threshold voltage of the PMOStransistor. Since the voltage of the drain output of the transistor P2does not reach the effect of the predetermined output Vgl, as shown inFIG. 2 , there is the tailing phenomenon when the output pulse signal ofthe existing shift register transitions from a high level to a low level(the position indicated by the arrow in FIG. 2 ).

In view of the above, the embodiments of the present disclosure providea display panel including a driver circuit. The driver circuit includesan N-stage cascaded shift register, N being greater than or equal to 2.The driver circuit is configured to output a pulse signal to the displaypanel row by row. For example, a scan pulse signal is outputted to eachscan line of the display panel, or a light emission control pulse signalis outputted to each row of light emission control signal lines of thedisplay panel. FIG. 3 is a structural diagram of a shift register of adisplay panel according to an embodiment of the present disclosure. Asshown in FIG. 3 , the shift register of the display panel provided bythe embodiment of the present disclosure includes a first control unit01, a second control unit 02, a third control unit 03, and a fourthcontrol unit 04. The first control unit 01 is configured to receive aninput signal IN and control a signal of a first node N1 in response to afirst clock signal CK1. The second control unit 02 is configured toreceive a first voltage signal Vgl and a second voltage signal Vgh andcontrol a signal of a second node N2 in response to the signal of thefirst node N1, the first clock signal CK1, and a second clock signalCK2. The third control unit 03 is configured to receive the firstvoltage signal Vgl and generate the output signal OUT in response to thesignal of a third node N3, or receive the second voltage signal Vgh andgenerate the output signal OUT in response to the signal of the secondnode N2, where the third node N3 is connected to the first node N1, thefirst voltage signal Vgl is a low level signal, and the second voltagesignal Vgh is a high level signal. In this embodiment of the presentdisclosure, the fourth control unit 04 is further provided. The fourthcontrol unit 04 is connected to the third node N3. The fourth controlunit 04 is configured to control the potential of the third node N3 tobe a first low level signal V1 for at least a first time period withintime when the first node N1 is a low level signal, where the potentialof the first low level signal V1 is lower than the potential of thefirst voltage signal Vgl. Therefore, the potential of the gate of atransistor for controlling the generation of the output signal OUT inthe third control unit 03 is smaller than the potential of the firstvoltage signal Vgl, and the potential of the source of this transistoris the potential of the first voltage signal Vgl. As a result, thetransistor for controlling the generation of the output signal OUT inthe third control unit 03 rapidly approaches the saturation state, thevoltage of the source and the voltage of the drain of the transistor forcontrolling the generation of the output signal OUT in the third controlunit 03 tend to be equal, and thus the tailing phenomenon can bereduced.

In an embodiment, on the basis of the above embodiment, the fourthcontrol unit may further include a first capacitor. The first plate ofthe first capacitor is connected to the third node, and the second plateof the first capacitor receives a first control signal, where the firstcontrol signal is a low level signal within the first time period. Forexample, with reference to FIG. 4 , the fourth control unit 04 isprovided with a first capacitor C1. The first plate of the firstcapacitor C1 is connected to the third node N3, and the second plate ofthe first capacitor C1 receives a first control signal A1. Within thefirst time period, the first node N1 is at a low level, the firstcontrol signal A1 is a low level signal, and the first capacitor C1 israpidly charged so that the potential of the third node N3 rapidly dropsand becomes lower than the potential of the first voltage signal Vgl.

In an embodiment, with reference to FIG. 5 , the fourth control unit 04may further include a first transistor M1. The source of the firsttransistor M1 receives the first control signal A1, the drain of thefirst transistor M1 is connected to the second plate of the firstcapacitor C1, and the gate of the first transistor M1 receives a secondcontrol signal A2, where within the first time period, the secondcontrol signal A2 controls the first transistor M1 to be on, the firstcontrol signal A1 is transmitted to the first capacitor C1, and in thispoint, the first node N1 is at a low potential. Under the low levelcontrol of the first capacitor C1 and the first control signal Al, thepotential of the third node N3 rapidly drops below the potential of thefirst voltage signal Vgl. When the third control unit 03 receives thesecond voltage signal Vgh and generates the output signal OUT inresponse to the signal of the second node N2, it is required that thethird node N3 always remains at a high potential. That is, the fourthcontrol unit 04 does not need to keep controlling the potential of thethird node N3 to be lower than the potential of the first voltage signalVgl. Therefore, in this embodiment of the present disclosure, the firsttransistor M1 is provided. Within the first time period, the firsttransistor M1 is on to control the potential of the third node N3 to belower than the potential of the first voltage signal Vgl, and withinother time periods, the first transistor M1 may be off to avoidinterfering with the potential of the third node N3 and affecting theoutput signal of the shift register.

In an embodiment, the first control signal and the second control signalmay further be set to be the same signal. For example, as shown in FIG.6 , the source and the gate of the first transistor M1 are connected toeach other, and both receive the first control signal A1 (or the secondcontrol signal A2). Such a setting can reduce the number of signal linesin the display panel.

In an embodiment, the first clock signal CK1 and the first controlsignal A1 may further be set to be the same signal. As shown in FIG. 7 ,in this embodiment of the present disclosure, the number of signal linesin the display panel can be further reduced. Through the adjustment ofthe timing of the shift register, the first clock signal CK1 is ensuredto be the low level signal within the first time period so that thefourth control unit can control the potential of the third node to bethe first low level signal, that is, the potential of the third node islower than the potential of the first voltage signal Vgl.

In an embodiment, the second control signal may further be set to be thesignal of the first node. As shown in FIG. 8 , the gate of the firsttransistor M1 is connected to the first node N1, and thus the secondcontrol signal A2 is the signal of the first node N1. When the firstnode N1 is at the low level, the first transistor M1 is on, and thefirst control signal A1 is transmitted to the first capacitor C1 so thatthe potential of the third node N3 is controlled to be lower than thepotential of the first voltage signal Vgl within the first time period.

In an embodiment, the fourth control unit in this embodiment of thepresent disclosure may further include a second capacitor. The firstplate of the second capacitor is connected to the gate of the firsttransistor, and the second plate of the second capacitor receives thesecond control signal. For example, as shown in FIG. 9 , the fourthcontrol unit 04 includes a second capacitor C2. The first plate of thesecond capacitor C2 is connected to the gate of the first transistor M1,and the second plate of the second capacitor C2 receives the secondcontrol signal Vgh. When the second control signal A2 is the signal ofthe first node N1, in this embodiment of the present disclosure, thepotential of the first node N1 may be stabilized through the secondvoltage signal Vgh and the second capacitor C2 to prevent the floatingof the potential of the first node N1 from affecting the potential ofthe third node N3.

In an embodiment, the capacitance value of the first capacitor is lessthan the capacitance value of the second capacitor. Since the firstcapacitor C1 is configured to control the pull-down of the potential ofthe third node, according to the relationship U=Q/C among thecapacitance C, the charge Q, and the voltage U, it can be seen that, inthe case where the charges are the same, a small capacitance value isrequired to make the voltage rapidly drop, and the smaller thecapacitance is, the faster the pull-down speed of the potential of thethird node is, the easier it is to improve the effect of reducing thetail phenomenon. Therefore, the first capacitor C1 requires a smallcapacitance value. The second capacitor C2 is mainly configured tostabilize the potential of the first node N1 and the potential of thethird node N3. Therefore, the second capacitor C2 requires a largecapacitance value to avoid causing a large change in the potential ofthe first node N1 in the process of charging and discharging thecapacitor, thereby improving the stability of the node potential.Therefore, in this embodiment of the present disclosure, the capacitancevalue of the first capacitor is set to be less than the capacitancevalue of the second capacitor.

In an embodiment, the fourth control unit may further include a secondtransistor. The source of the second transistor is connected to thefirst node, the drain of the second transistor is connected to the thirdnode, and the gate of the second transistor receives the first controlsignal, where the second control signal controls the first transistor tobe on within the first time period. As shown in FIG. 10 , the fourthcontrol unit 04 includes a first capacitor C1, a first transistor M1,and a second transistor M2. The source of the first transistor M1receives the first control signal A1, the drain of the first transistorM1 is connected to the third node N3, and the gate of the firsttransistor M1 receives the second control signal A2. The first capacitorC1 is located between the drain of the first transistor M1 and the thirdnode N3. Within the first time period, the second control signal A2controls the first transistor M1 to be on, and the first control signalA1 is a low level signal within the first time period. The source of thesecond capacitor M2 is connected to the first node N1, the drain of thesecond transistor M2 is connected to the third node N3, and the gate ofthe second transistor M2 receives the first control signal A1, where thefirst control signal A1 controls the second transistor M2 to be onwithin the first time period.

If the potential of the first node N1 is transmitted to the third nodeN3 before the first control signal A1 drops to the low level, thetailing problem of the shift register cannot be avoided. In thisembodiment of the present disclosure, the second transistor M2 isprovided between the first node N1 and the third node N3. Since the gateof the second transistor M2 receives the first control signal A1, onlywhen the first control signal A1 is at the low level, the firsttransistor M1 is on and the second transistor M2 is on, is the pull-downof the potential of the third node N3 achieved so that the output signaltailing problem generated due to the direct transmission of thepotential of the first node N1 to the third control unit 03 without thepull-down function of the fourth control unit 04 can be prevented.

In an embodiment, the fourth control unit may further include a thirdcapacitor. The source of the third capacitor receives the second voltagesignal, the drain of the third transistor is connected to the thirdnode, and the gate of the third transistor is connected to the secondnode, where the second node controls the third transistor to be offwithin the first time period. For example, as shown in FIG. 11 , thefourth control unit 04 includes a first capacitor C1, a first transistorM1, and a third transistor M3. The source of the first transistor M1receives the first control signal A1, the drain of the first transistorM1 is connected to the third node N3, and the gate of the firsttransistor M1 receives the second control signal A2. The first capacitorC1 is located between the drain of the first transistor M1 and the thirdnode N3. Within the first time period, the second control signal A2controls the first transistor M1 to be on, and the first control signalA1 is a low level signal within the first time period. The source of thethird capacitor M3 receives the second voltage signal Vgh, the drain ofthe third transistor M3 is connected to the third node N3, and the gateof the third transistor M3 is connected to the second node N2, where thesecond node N2 controls the third transistor M3 to be off within thefirst time period.

Since each clock signal in the shift register is subjected to multipletransitions, the potential of the first node N1 and the potential of thethird node N3 float in the transition process. In this embodiment of thepresent disclosure, the third transistor M3 is provided, and thepotential of the third node N3 is controlled by the potential of thesecond node N2 to ensure the signal stability when the third node N3 isat the high level. For example, if the shift register is required tooutput a high level (the second voltage signal Vgh), the second node N2is at a low potential, and the third node N3 is required to remain at astable high potential. In this embodiment of the present disclosure, thethird transistor M3 is provided, the gate of the third transistor M3 isconnected to the second node N2, the second node N2 is at a lowpotential, and the third transistor M3 is on so that the third node N3is stably remained at the high potential of the second voltage signalVgh, thereby ensuring that the level of the third node N3 does notchange until the second node N2 becomes a high level. Only when thesecond node N2 becomes a high level can the third node N3 become a lowlevel signal lower than the first voltage signal Vgl, thereby reducingthe tailing phenomenon.

In an embodiment, the first control unit may include a fourthtransistor. The source of the fourth transistor receives the inputsignal, the drain of the fourth transistor is connected to the firstnode, and the gate of the fourth transistor receives the first clocksignal. The second control unit includes a fifth transistor, a sixthtransistor, a seventh transistor, an eighth transistor, a ninthtransistor, a third capacitor, and a fourth capacitor. The source of thefifth transistor receives the first clock signal, the drain of the fifthtransistor is connected to a fourth node, and the gate of the fifthtransistor is connected to the first node. The source of the sixthtransistor receives the second clock signal, the drain of the sixthtransistor is connected to a fifth node, and the gate of the sixthtransistor is connected to the fourth node. The source of the seventhtransistor receives the first voltage signal, the drain of the seventhtransistor is connected to the fourth node, and the gate of the seventhtransistor receives the first clock signal. The source of the eighthtransistor receives the second voltage signal, the drain of the eighthtransistor is connected to the second node, and the gate of the eighthtransistor is connected to the first node. The source of the ninthtransistor is connected to the fifth node, the drain of the ninthtransistor is connected to the second node, and the gate of the ninthtransistor receives the second clock signal. The first plate of thethird capacitor is connected to the fourth node, and the second plate ofthe third capacitor is connected to the fifth node. The first plate ofthe fourth capacitor receives the second voltage signal, and the secondplate of the fourth capacitor is connected to the second node. The thirdcontrol unit includes a tenth transistor, an eleventh transistor, and afourth capacitor. The source of the tenth transistor receives the firstvoltage signal, the drain of the tenth transistor outputs an outputsignal, and the gate of the tenth transistor is connected to the thirdnode. The source of the eleventh transistor receives the second voltagesignal, the drain of the eleventh transistor outputs an output signal,and the gate of the eleventh transistor is connected to the second node.

For example, with reference to FIG. 12 , the first control unit 01 mayinclude a fourth transistor M4. The source of the fourth transistor M4receives the input signal IN, the drain of the fourth transistor M4 isconnected to the first node N1, and the gate of the fourth transistor M4receives the first clock signal CK1. The second control unit 02 includesa fifth transistor M5, a sixth transistor M6, a seventh transistor M7,an eighth transistor M8, a ninth transistor M9, a third capacitor C3,and a fourth capacitor C4. The source of the fifth transistor M5receives the first clock signal CK1, the drain of the fifth transistorM5 is connected to a fourth node N4, and the gate of the fifthtransistor M5 is connected to the first node N1. The source of the sixthtransistor M6 receives the second clock signal CK2, the drain of thesixth transistor M6 is connected to a fifth node N5, and the gate of thesixth transistor M6 is connected to the fourth node N4. The source ofthe seventh transistor M7 receives the first voltage signal Vgl, thedrain of the seventh transistor M7 is connected to the fourth node N4,and the gate of the seventh transistor M7 receives the first clocksignal CK1. The source of the eighth transistor M8 receives the secondvoltage signal Vgh, the drain of the eighth transistor M8 is connectedto the second node N2, and the gate of the eighth transistor M8 isconnected to the first node N1. The source of the ninth transistor M9 isconnected to the fifth node N5, the drain of the ninth transistor M9 isconnected to the second node N2, and the gate of the ninth transistor M9receives the second clock signal CK2. The first plate of the thirdcapacitor C3 is connected to the fourth node N4, and the second plate ofthe third capacitor C3 is connected to the fifth node N5. The firstplate of the fourth capacitor C4 receives the second voltage signal Vgh,and the second plate of the fourth capacitor C4 is connected to thesecond node N2. The third control unit 03 includes a tenth transistorM10, an eleventh transistor M11, and a fourth capacitor C4. The sourceof the tenth transistor M10 receives the first voltage signal Vgl, thedrain of the tenth transistor M10 outputs an output signal OUT, and thegate of the tenth transistor M10 is connected to the third node N3. Thesource of the eleventh transistor M11 receives the second voltage signalVgh, the drain of the eleventh transistor M11 outputs an output signalOUT, and the gate of the eleventh transistor M11 is connected to thesecond node N2.

In an embodiment, the capacitance value of the first capacitor C1 isless than the capacitance value of the third capacitor C3, or thecapacitance value of the first capacitor C1 is less than the capacitancevalue of the fourth capacitor C4. Since the first capacitor C1 isconfigured to control the pull-down of the potential of the third nodeN3, the smaller the capacitance is, the faster the pull-down speed ofthe potential of the third node N3 is, the easier it is to improve theeffect of reducing the tail phenomenon. Therefore, the capacitance valueof the first capacitor C1 is set to be less than the capacitance valueof the third capacitor C3, or the capacitance value of the firstcapacitor C1 is set to be less than the capacitance value of the fourthcapacitor C4. The third capacitor C3 is mainly configured to stabilizethe potential of the fourth node N4, and the fourth capacitor C4 isconfigured to stabilize the potential of the second node N2. Therefore,the capacitance value of both the third capacitor C3 and the fourthcapacitor C4 is set to be larger than the capacitance value of the firstcapacitor C1.

The specific implementation principle of the present disclosure will bedescribed in detail below with reference to several specific examples ofthe circuit structure of the shift register. FIG. 13 is a schematicdiagram of the circuit structure of another shift register according toan embodiment of the present disclosure. As shown in FIG. 13 , the firstcontrol unit 01 includes a fourth transistor M4. The source of thefourth transistor M4 receives the input signal IN, the drain of thefourth transistor M4 is connected to the first node N1, and the gate ofthe fourth transistor M4 receives the first clock signal CK1. The secondcontrol unit 02 includes a fifth transistor M5, a sixth transistor M6, aseventh transistor M7, an eighth transistor M8, a ninth transistor M9, athird capacitor C3, and a fourth capacitor C4. The source of the fifthtransistor M5 receives the first clock signal CK1, the drain of thefifth transistor M5 is connected to the fourth node N4, and the gate ofthe fifth transistor M5 is connected to the first node N1. The source ofthe sixth transistor M6 receives the second clock signal CK2, the drainof the sixth transistor M6 is connected to the fifth node N5, and thegate of the sixth transistor

M6 is connected to the fourth node N4. The source of the seventhtransistor M7 receives the first voltage signal Vgl, the drain of theseventh transistor M7 is connected to the fourth node N4, and the gateof the seventh transistor M7 receives the first clock signal CK1. Thesource of the eighth transistor M8 receives the second voltage signalVgh, the drain of the eighth transistor M8 is connected to the secondnode N2, and the gate of the eighth transistor M8 is connected to thefirst node N1. The source of the ninth transistor M9 is connected to thefifth node N5, the drain of the ninth transistor M9 is connected to thesecond node N2, and the gate of the ninth transistor M9 receives thesecond clock signal CK2. The first plate of the third capacitor C3 isconnected to the fourth node N4, and the second plate of the thirdcapacitor C3 is connected to the fifth node N5. The first plate of thefourth capacitor C4 receives the second voltage signal Vgh, and thesecond plate of the fourth capacitor C4 is connected to the second nodeN2. The third control unit 03 includes a tenth transistor M10, aneleventh transistor M11, and a fourth capacitor C4. The source of thetenth transistor M10 receives the first voltage signal Vgl, the drain ofthe tenth transistor M10 outputs the output signal OUT, and the gate ofthe tenth transistor M10 is connected to the third node N3. The sourceof the eleventh transistor M11 receives the second voltage signal Vgh,the drain of the eleventh transistor M11 outputs the output signal OUT,and the gate of the eleventh transistor M11 is connected to the secondnode N2. The fourth control unit 04 includes a first capacitor C1. Thefirst plate of the first capacitor Cl is connected to the third node N3,and the second plate of the first capacitor C1 receives the firstcontrol signal A1. The fourth control unit 04 includes a firsttransistor Ml. The source of the first transistor M1 receives the firstcontrol signal A1, the drain of the first transistor M1 is connected tothe second plate of the first capacitor C1, and the gate of the firsttransistor M1 receives the second control signal A2. In this embodiment,the first clock signal, the first control signal A1, and the secondcontrol signal A2 are the same signal. Within the first time period, thefirst control signal A1 is a low level signal, and the second controlsignal A2 controls the first transistor M1 to be on. FIG. 14 is a timingdiagram of the circuit structure shown in FIG. 13 . The timing will bedescribed in detail below with reference to FIGS. 13 and 14 .

At the first stage T1, the input signal IN is at a high level, the firstclock signal CK1 is at a low level, the fourth transistor M4 is on, thefirst node N1 is at a high level, and the third node N3 is at a highlevel. The seventh transistor M7 is on, and the fourth node N4 is at alow level. The second clock signal CK2 is at a high level, the secondnode N2 remains at a high level, the eleventh transistor M11 is off, andthe output signal OUT remains at a low level.

At the second stage T2, the input signal IN is at a high level, thefirst clock signal CK1 is at a high level, the fourth transistor M4 isoff, the first node N1 remains at a high level, and the third node N3remains at a high level. The fourth node N4 remains at a low level, thesecond clock signal CK2 is at a low level, the sixth transistor M6 andthe ninth transistor M9 are on, the second node N2 becomes at a lowlevel, the eleventh transistor M11 is on, and the output signal OUTbecomes at a high level.

At the third stage T3, the input signal IN is at a high level, the firstclock signal CK1 is at a low level, the first node N1 is at a highlevel, the third node N3 is at a high level, the seventh transistor M7is on, the fourth node N4 is at a low level, the second clock signal CK2is at a high level, the sixth transistor M6 is on, the fifth node N5 isat a high level, the ninth transistor M9 is off, the second node N2remains at a low level, the eleventh transistor M11 is on, and theoutput signal OUT remains at a high level.

At the fourth stage T4, the input signal IN is at a low level, the firstclock signal CK1 is at a high level, the first node N1 remains at a highlevel, the third node N3 remains at a high level, the fourth node N4remains at a low level, the second clock signal CK2 is at a low level,the second node N2 is at a low level, and the output signal OUT remainsat a high level.

At the fifth stage T5, the input signal IN is at a low level, the firstclock signal CK1 is at a low level, and the first node N1 is at a lowlevel. Within the first time period X1, the first transistor M1 is on,and the first capacitor C1 is rapidly charged so that the potential ofthe third node N3 rapidly drops to the first low level signal V1. Thefourth node N4 is at a low level, the second clock signal CK2 is at ahigh level, and the second node N2 is at a high level. Since thepotential of the first low level signal V1 is lower than the potentialof the first voltage signal Vgl and the potential of the gate of thetenth transistor M10 is less than the potential of the source of thetenth transistor M10, the tenth transistor M10 can rapidly approach thesaturation state, the tenth transistor M10 is on, the eleventhtransistor M11 is off, and the output signal OUT of the shift registersubstantially coincides with the first voltage signal Vgl, therebyavoiding the tailing phenomenon of the output signal.

FIG. 15 is a schematic diagram of the circuit structure of another shiftregister according to an embodiment of the present disclosure. As shownin FIG. 15 , the first control unit 01 includes a fourth transistor M4.The source of the fourth transistor M4 receives the input signal IN, thedrain of the fourth transistor M4 is connected to the first node N1, andthe gate of the fourth transistor M4 receives the first clock signalCK1. The second control unit 02 includes a fifth transistor M5, a sixthtransistor M6, a seventh transistor M7, an eighth transistor M8, a ninthtransistor M9, a third capacitor C3, and a fourth capacitor C4. Thesource of the fifth transistor M5 receives the first clock signal CK1,the drain of the fifth transistor M5 is connected to the fourth node N4,and the gate of the fifth transistor M5 is connected to the first nodeN1. The source of the sixth transistor M6 receives the second clocksignal CK2, the drain of the sixth transistor M6 is connected to thefifth node N5, and the gate of the sixth transistor

M6 is connected to the fourth node N4. The source of the seventhtransistor M7 receives the first voltage signal Vgl, the drain of theseventh transistor M7 is connected to the fourth node N4, and the gateof the seventh transistor M7 receives the first clock signal CK1. Thesource of the eighth transistor M8 receives the second voltage signalVgh, the drain of the eighth transistor M8 is connected to the secondnode N2, and the gate of the eighth transistor M8 is connected to thefirst node N1. The source of the ninth transistor M9 is connected to thefifth node N5, the drain of the ninth transistor M9 is connected to thesecond node N2, and the gate of the ninth transistor M9 receives thesecond clock signal CK2. The first plate of the third capacitor C3 isconnected to the fourth node N4, and the second plate of the thirdcapacitor C3 is connected to the fifth node N5. The first plate of thefourth capacitor C4 receives the second voltage signal Vgh, and thesecond plate of the fourth capacitor C4 is connected to the second nodeN2. The third control unit 03 includes a tenth transistor M10, aneleventh transistor M11, and a fourth capacitor C4. The source of thetenth transistor M10 receives the first voltage signal Vgl, the drain ofthe tenth transistor M10 outputs the output signal OUT, and the gate ofthe tenth transistor M10 is connected to the third node N3. The sourceof the eleventh transistor M11 receives the second voltage signal Vgh,the drain of the eleventh transistor M11 outputs the output signal OUT,and the gate of the eleventh transistor M11 is connected to the secondnode N2. The fourth control unit 04 includes a first capacitor C1. Thefirst plate of the first capacitor C1 is connected to the third node N3,and the second plate of the first capacitor C1 receives the firstcontrol signal A1. The fourth control unit 04 includes a firsttransistor M1. The source of the first transistor M1 receives the firstcontrol signal A1, the drain of the first transistor M1 is connected tothe second plate of the first capacitor C1, and the gate of the firsttransistor M1 receives the second control signal A2. In this embodiment,the second control signal A2 is the signal of the first node N1. Thefirst clock CK1 and the first control signal A1 are the same signal.Within the first time period, the first control signal A1 is a low levelsignal, and the second control signal A2 controls the first transistorM1 to be on. FIG. 16 is a timing diagram of the circuit structure shownin FIG. 16 . The timing will be described in detail below with referenceto FIGS. 15 and 16 .

At the first stage T1, the input signal IN is at a high level, the firstclock signal CK1 is at a low level, the fourth transistor M4 is on, thefirst node N1 is at a high level, the third node N3 is at a high level,the seventh transistor M7 is on, and the fourth node N4 is at a lowlevel. The second clock signal CK2 is at a high level, the second nodeN2 remains at a high level, the eleventh transistor M11 is off, and theoutput signal OUT remains at a low level.

At the second stage T2, the input signal IN is at a high level, thefirst clock signal CK1 is at a high level, the fourth transistor M4 isoff, the first node N1 remains at a high level, and the third node N3remains at a high level. The fourth node N4 remains at a low level, thesecond clock signal CK2 is at a low level, the sixth transistor M6 andthe ninth transistor M9 are on, the second node N2 becomes at a lowlevel, the eleventh transistor M11 is on, and the output signal OUTbecomes at a high level.

At the third stage T3, the input signal IN is at a high level, the firstclock signal CK1 is at a low level, the first node N1 is at a highlevel, the third node N3 is at a high level, the seventh transistor M7is on, the fourth node N4 is at a low level, the second clock signal CK2is at a high level, the sixth transistor M6 is on, the fifth node N5 isat a high level, the ninth transistor M9 is off, the second node N2remains at a low level, the eleventh transistor M11 is on, and theoutput signal OUT remains at a high level.

At the fourth stage T4, the input signal IN is at a low level, the firstclock signal CK1 is at a high level, the first node N1 remains at a highlevel, the third node N3 remains at a high level, the fourth node N4remains at a low level, the second clock signal CK2 is at a low level,the second node N2 is at a low level, and the output signal OUT remainsat a high level.

At the fifth stage T5, the input signal IN is at a low level, the firstclock signal CK1 is at a low level, the first node N1 is at a low level,and the gate of the first transistor M1 is connected to the first nodeN1. Therefore, within the first time period X1, the first transistor M1is on, and the first capacitor C1 is rapidly charged so that thepotential of the third node N3 rapidly drops to the potential of thefirst low level signal V1. The fourth node N4 is at a low level, thesecond clock signal CK2 is at a high level, and the second node N2 is ata high level. Since the potential of the first low level signal V1 islower than the potential of the first voltage signal Vgl and thepotential of the gate of the tenth transistor M10 is less than thepotential of the source of the tenth transistor M10, the tenthtransistor M10 can rapidly approach the saturation state, the tenthtransistor M10 is on, the eleventh transistor M11 is off, and the outputsignal OUT of the shift register substantially coincides with the firstvoltage signal Vgl, thereby avoiding the tailing phenomenon of theoutput signal.

FIG. 17 is a schematic diagram of the circuit structure of another shiftregister according to an embodiment of the present disclosure. As shownin FIG. 17 , the first control unit 01 includes a fourth transistor M4.The source of the fourth transistor M4 receives the input signal IN, thedrain of the fourth transistor M4 is connected to the first node N1, andthe gate of the fourth transistor M4 receives the first clock signalCK1. The second control unit 02 includes a fifth transistor M5, a sixthtransistor M6, a seventh transistor M7, an eighth transistor M8, a ninthtransistor M9, a third capacitor C3, and a fourth capacitor C4. Thesource of the fifth transistor M5 receives the first clock signal CK1,the drain of the fifth transistor M5 is connected to the fourth node N4,and the gate of the fifth transistor M5 is connected to the first nodeN1. The source of the sixth transistor M6 receives the second clocksignal CK2, the drain of the sixth transistor M6 is connected to thefifth node N5, and the gate of the sixth transistor M6 is connected tothe fourth node N4. The source of the seventh transistor M7 receives thefirst voltage signal Vgl, the drain of the seventh transistor M7 isconnected to the fourth node N4, and the gate of the seventh transistorM7 receives the first clock signal CK1. The source of the eighthtransistor M8 receives the second voltage signal Vgh, the drain of theeighth transistor M8 is connected to the second node N2, and the gate ofthe eighth transistor M8 is connected to the first node N1. The sourceof the ninth transistor M9 is connected to the fifth node N5, the drainof the ninth transistor M9 is connected to the second node N2, and thegate of the ninth transistor M9 receives the second clock signal CK2.The first plate of the third capacitor C3 is connected to the fourthnode N4, and the second plate of the third capacitor C3 is connected tothe fifth node N5. The first plate of the fourth capacitor C4 receivesthe second voltage signal Vgh, and the second plate of the fourthcapacitor C4 is connected to the second node N2. The third control unit03 includes a tenth transistor M10, an eleventh transistor M11, and afourth capacitor C4. The source of the tenth transistor M10 receives thefirst voltage signal Vgl, the drain of the tenth transistor M10 outputsthe output signal OUT, and the gate of the tenth transistor M10 isconnected to the third node N3. The source of the eleventh transistorM11 receives the second voltage signal Vgh, the drain of the eleventhtransistor M11 outputs the output signal OUT, and the gate of theeleventh transistor M11 is connected to the second node N2. The fourthcontrol unit 04 includes a first capacitor C1, a first transistor, and asecond capacitor C2. The first plate of the first capacitor C1 isconnected to the third node N3, and the second plate of the firstcapacitor C1 receives the first control signal A1. The source of thefirst transistor M1 receives the first control signal A1, the drain ofthe first transistor M1 is connected to the second plate of the firstcapacitor C1, and the gate of the first transistor M1 receives thesecond control signal A2. The first plate of the second capacitor C2 isconnected to the gate of the first transistor M1, and the second plateof the second capacitor C2 receives the second voltage signal Vgh. Thegate of the first transistor M1 is connected to the first node N1, thatis, the second control signal A2 is a potential signal of the first nodeN1. In this embodiment, the first clock CK1 and the first control signalA1 are the same signal. Within the first time period, the first controlsignal A1 is a low level signal, and the second control signal A2controls the first transistor M1 to be on. FIG. 18 is a timing diagramof the circuit structure shown in FIG. 17 . The timing will be describedin detail below with reference to FIGS. 17 and 18 .

At the first stage T1, the input signal IN is at a high level, the firstclock signal CK1 is at a low level, the fourth transistor M4 is on, thefirst node N1 is at a high level, the third node N3 is at a high level,the seventh transistor M7 is on, and the fourth node N4 is at a lowlevel. The second clock signal CK2 is at a high level, the second nodeN2 remains at a high level, the eleventh transistor M11 is off, and theoutput signal OUT remains at a low level.

At the second stage T2, the input signal IN is at a high level, thefirst clock signal CK1 is at a high level, the fourth transistor M4 isoff, the first node N1 remains at a high level, and the third node N3remains at a high level. The fourth node N4 remains at a low level, thesecond clock signal CK2 is at a low level, the sixth transistor M6 andthe ninth transistor M9 are on, the second node N2 becomes at a lowlevel, the eleventh transistor Mi i is on, and the output signal OUTbecomes at a high level.

At the third stage T3, the input signal IN is at a high level, the firstclock signal CK1 is at a low level, the first node N1 is at a highlevel, the third node N3 is at a high level, the seventh transistor M7is on, the fourth node N4 is at a low level, the second clock signal CK2is at a high level, the sixth transistor M6 is on, the fifth node N5 isat a high level, the ninth transistor M9 is off, the second node N2remains at a low level, the eleventh transistor M11 is on, and theoutput signal OUT remains at a high level.

At the fourth stage T4, the input signal IN is at a low level, the firstclock signal CK1 is at a high level, the first node N1 remains at a highlevel, the third node N3 remains at a high level, the fourth node N4remains at a low level, the second clock signal CK2 is at a low level,the second node N2 is at a low level, and the output signal OUT remainsat a high level.

At the fifth stage T5, the input signal IN is at a low level, the firstclock signal CK1 is at a low level, and the first node N1 is at a lowlevel. Within the first time period X1, the gate of the first transistorM1 is connected to the first node N1. Therefore, the first transistor M1is on, and the first capacitor C1 is rapidly charged so that thepotential of the third node N3 rapidly drops to the potential of thefirst low level signal V1. The fourth node N4 is at a low level, thesecond clock signal CK2 is at a high level, and the second node N2 is ata high level. Since the potential of the first low level signal V1 islower than the potential of the first voltage signal Vgl and thepotential of the gate of the tenth transistor M10 is less than thepotential of the source of the tenth transistor M10, the tenthtransistor M10 can rapidly approach the saturation state, the tenthtransistor M10 is on, the eleventh transistor M11 is off, and the outputsignal OUT of the shift register substantially coincides with the firstvoltage signal Vgl, thereby avoiding the tailing phenomenon of theoutput signal. The fourth control unit 04 in this embodiment of thepresent disclosure is provided with a second capacitor C2. The potentialof the first node N1 may be stabilized by the second voltage signal Vghand the second capacitor C2 so that the floating of the potential of thefirst node N1 is prevented from affecting the potential of the thirdnode N3 and thus affecting the output signal OUT of the shift register.

FIG. 19 is a schematic diagram of the circuit structure of another shiftregister according to an embodiment of the present disclosure. As shownin FIG. 19 , the first control unit 01 includes a fourth transistor M4.The source of the fourth transistor M4 receives the input signal IN, thedrain of the fourth transistor M4 is connected to the first node N1, andthe gate of the fourth transistor M4 receives the first clock signalCK1. The second control unit 02 includes a fifth transistor M5, a sixthtransistor M6, a seventh transistor M7, an eighth transistor M8, a ninthtransistor M9, a third capacitor C3, and a fourth capacitor C4. Thesource of the fifth transistor M5 receives the first clock signal CK1,the drain of the fifth transistor M5 is connected to the fourth node N4,and the gate of the fifth transistor M5 is connected to the first nodeN1. The source of the sixth transistor M6 receives the second clocksignal CK2, the drain of the sixth transistor M6 is connected to thefifth node N5, and the gate of the sixth transistor M6 is connected tothe fourth node N4. The source of the seventh transistor M7 receives thefirst voltage signal Vgl, the drain of the seventh transistor M7 isconnected to the fourth node N4, and the gate of the seventh transistorM7 receives the first clock signal CK1. The source of the seventhtransistor M7 receives the first voltage signal Vgl, the drain of theseventh transistor M7 is connected to the fourth node N4, and the gateof the seventh transistor M7 receives the first clock signal CK1. Thesource of the eighth transistor M8 receives the second voltage signalVgh, the drain of the eighth transistor M8 is connected to the secondnode N2, and the gate of the eighth transistor M8 is connected to thefirst node N1. The source of the ninth transistor M9 is connected to thefifth node N5, the drain of the ninth transistor M9 is connected to thesecond node N2, and the gate of the ninth transistor M9 receives thesecond clock signal CK2. The first plate of the third capacitor C3 isconnected to the fourth node N4, and the second plate of the thirdcapacitor C3 is connected to the fifth node N5. The first plate of thefourth capacitor C4 receives the second voltage signal Vgh, and thesecond plate of the fourth capacitor C4 is connected to the second nodeN2. The third control unit 03 includes a tenth transistor M10, aneleventh transistor M11, and a fourth capacitor C4. The source of thetenth transistor M10 receives the first voltage signal Vgl, the drain ofthe tenth transistor M10 outputs the output signal OUT, and the gate ofthe tenth transistor M10 is connected to the third node N3. The sourceof the eleventh transistor M11 receives the second voltage signal Vgh,the drain of the eleventh transistor M11 outputs the output signal OUT,and the gate of the eleventh transistor M11 is connected to the secondnode N2. The fourth control unit 04 includes a first capacitor C1, afirst transistor M1, a second capacitor C2, and a second transistor M2.The first plate of the first capacitor C1 is connected to the third nodeN3, and the second plate of the first capacitor C1 receives the firstcontrol signal A1. The source of the first transistor M1 receives thefirst control signal A1, the drain of the first transistor M1 isconnected to the second plate of the first capacitor C1, and the gate ofthe first transistor M1 receives the second control signal A2. The firstplate of the second capacitor C2 is connected to the gate of the firsttransistor M1, and the second plate of the second capacitor C2 receivesthe second voltage signal Vgh. The gate of the first transistor M1 isconnected to the first node N1, that is, the second control signal A2 isa potential signal of the first node N1. The source of the secondtransistor M2 is connected to the first node N1, the drain of the secondtransistor M2 is connected to the third node N3, and the gate of thesecond transistor M2 receives the first control signal A1. Within thefirst time period, the first control signal A1 controls the secondtransistor M2 to be on, the first control signal A1 is a low levelsignal, and the second control signal A2 controls the first transistorM1 to be on. FIG. 20 is a timing diagram of the circuit structure shownin FIG. 19 . The timing will be described in detail below with referenceto FIGS. 19 and 20 .

At the first stage T1, the input signal IN is at a high level, the firstclock signal CK1 is at a low level, the second clock signal CK2 is at ahigh level, the fourth transistor M4 is on, the first node N1 is at ahigh level, the fourth node N4 is at a low level, the first controlsignal A1 is at a high level, the second transistor M2 is off, the thirdnode N3 remains at a low level, the second node N2 is at a high level,and the output signal OUT is at a low level.

At the second stage T2, the input signal IN is at a high level, thefirst control signal A1 is at a low level, the second clock signal CK2is at a high level, the first node N1 is at a high level, the secondtransistor M2 is on, the third node N3 is at a high level, the fourthnode N4 is at a low level, the second node N2 is at a high level, andthe output signal OUT remains at a low level.

At the third stage T3, the input signal IN is at a high level, thesecond clock signal CK2 is at a low level, the first node N1 is at ahigh level, the third node N3 is at a high level, the fourth node N4 isat a low level, the sixth transistor M6 and the ninth transistor M9 areon, the second node N2 becomes at a low level, the eleventh transistorM11 is on, and the output signal OUT remains at a low level.

At the fourth stage T4, the input signal IN is at a high level, thesecond clock signal CK2 is at a high level, the first node N1 is at ahigh level, the third node N3 is at a high level, the fourth node N4 isat a low level, the second node N2 is at a low level, and the outputsignal OUT remains at a high level.

At the fifth stage T5, the input signal IN is at a low level, the firstclock signal CK1 is at a high level, the first control signal A1 is at ahigh level, the second clock signal CK2 is at a low level, the firstnode N1 is at a high level, the third node N3 is at a high level, thefourth node N4 is at a low level, the second node N2 is at a low level,and the output signal OUT remains at a high level.

At the sixth stage T6, the input signal IN is at a low level, the firstclock signal CK1 is at a low level, the second clock signal CK2 is at ahigh level, the first node N1 is at a low level, the fifth transistor M5is on, the fourth node N4 is at a low level, the first control signal A1is at a high level, the second transistor M2 is off, and the third nodeN3 is at a high level. Since the eighth transistor M8 is on, the secondnode N2 becomes at a high level, the tenth transistor M10 and theeleventh transistor Mi i are off, and the output signal OUT remains at ahigh level.

At the seventh stage T7, the input signal IN is at a low level, thefirst control signal A1 is at a low level, and the first node N1 is at alow level. Within the first time period X1, the first capacitor C1 israpidly charged and thus pulls down the potential of the first node N1to the potential of the first low level signal V1 so that the potentialof the first low level signal V1 is less than the potential of the firstvoltage signal Vgl, and the second transistor M2 is on, so the potentialof the third node N3 is the potential of the first low level signal V1.The fourth node N4 and the second node N2 both are on, and the eleventhtransistor M11 is off. Since the potential of the third node N3 is lessthan the potential of the first voltage signal Vgl, the potential of thegate of the tenth transistor M10 is less than the potential of thesource of the tenth transistor M10, the tenth transistor M10 can rapidlyapproach a saturation state, the tenth transistor M10 is on, and theoutput signal OUT of the shift register substantially coincides with thefirst voltage signal Vgl, thereby avoiding the tailing phenomenon of theoutput signal.

FIG. 21 is a schematic diagram of the circuit structure of another shiftregister according to an embodiment of the present disclosure. As shownin FIG. 21 , the first control unit 01 includes a fourth transistor M4.The source of the fourth transistor M4 receives the input signal IN, thedrain of the fourth transistor M4 is connected to the first node N1, andthe gate of the fourth transistor M4 receives the first clock signalCK1. The second control unit 02 includes a fifth transistor M5, a sixthtransistor M6, a seventh transistor M7, an eighth transistor M8, a ninthtransistor M9, a third capacitor C3, and a fourth capacitor C4. Thesource of the fifth transistor M5 receives the first clock signal CK1,the drain of the fifth transistor M5 is connected to the fourth node N4,and the gate of the fifth transistor M5 is connected to the first nodeN1. The source of the sixth transistor M6 receives the second clocksignal CK2, the drain of the sixth transistor M6 is connected to thefifth node N5, and the gate of the sixth transistor M6 is connected tothe fourth node N4. The source of the seventh transistor M7 receives thefirst voltage signal Vgl, the drain of the seventh transistor M7 isconnected to the fourth node M4, and the gate of the seventh transistorM7 receives the first clock signal CK1. The source of the eighthtransistor M8 receives the second voltage signal Vgh, the drain of theeighth transistor M8 is connected to the second node N2, and the gate ofthe eighth transistor M8 is connected to the first node N1. The sourceof the ninth transistor M9 is connected to the fifth node N5, the drainof the ninth transistor M9 is connected to the second node N2, and thegate of the ninth transistor M9 receives the second clock signal CK2.The first plate of the third capacitor C3 is connected to the fourthnode N4, and the second plate of the third capacitor C3 is connected tothe fifth node N5. The first plate of the fourth capacitor C4 receivesthe second voltage signal Vgh, and the second plate of the fourthcapacitor C4 is connected to the second node N2. The third control unit03 includes a tenth transistor M10, an eleventh transistor M11, and afourth capacitor C4. The source of the tenth transistor M10 receives thefirst voltage signal Vgl, the drain of the tenth transistor M10 outputsthe output signal OUT, and the gate of the tenth transistor M10 isconnected to the third node N3. The source of the eleventh transistorM11 receives the second voltage signal Vgh, the drain of the eleventhtransistor M11 outputs the output signal OUT, and the gate of theeleventh transistor M11 is connected to the second node N2. The fourthcontrol unit 04 includes a first capacitor C1. The first plate of thefirst capacitor C1 is connected to the third node N3, and the secondplate of the first capacitor C1 receives the first control signal A1.The fourth control unit 04 includes a first capacitor C1. The firstplate of the first capacitor C1 is connected to the third node N3, andthe second plate of the first capacitor C1 receives the first controlsignal A1. The fourth control unit 04 includes a first transistor M1.The source of the first transistor M1 receives the first control signalA1, the drain of the first transistor M1 is connected to the secondplate of the first capacitor C1, and the gate of the first transistor M1receives the second control signal A2. In this embodiment, the secondcontrol signal A2 is the signal of the first node N1. Within the firsttime period, the first control signal A1 is a low level signal, and thesecond control signal A2 controls the first transistor M1 to be on. Inaddition, the fourth control unit 04 further includes a secondtransistor M2. The source of the second transistor M2 is connected tothe first node N1, the drain of the second transistor M2 is connected tothe third node N3, the gate of the second transistor M2 receives thefirst control signal A1, and the first control signal A1 controls thesecond transistor M2 to be on within the first time period. FIG. 22 is atiming diagram of the circuit structure shown in FIG. 21 . The timingwill be described in detail below with reference to FIGS. 21 and 22 .

At the first stage T1, the input signal IN is at a high level, the firstclock signal CK1 is at a low level, the second clock signal CK2 is at ahigh level, the fourth transistor M4 is on, the first node N1 is at ahigh level, the first control signal A1 is at a high level, the secondtransistor M2 is off, the third node N3 remains at a high potential, theseventh transistor M7 is on, and the fourth node N4 is at a low level.The second node N2 is at a high level, the eleventh transistor M11 isoff, the tenth transistor M10 is on, and the output signal OUT is at alow level.

At the second stage T2, the input signal IN is at a high level, thefirst clock signal CK1 is at a high level, the first control signal A1is at a low level, the second clock signal CK2 is at a high level, thefirst node N1 is at a high level, the second transistor M2 is on, thethird node N3 is at a high level, the fourth node N4 is at a low level,the second node N2 is at a low level, and the output signal OUT remainsat a low level.

At the third stage T3, the input signal IN is at a high level, the firstclock signal CK1 is at a high level, the first control signal A1 is at alow level, the first control signal A1 is at a high level, the firstnode N1 is at a high level, the third node N3 is at a high level, thefourth node N4 is at a low level, the sixth transistor M6 and the ninthtransistor M9 are both on, the second node N2 is at a low level, theeleventh transistor Mll is on, and the output signal OUT remains at ahigh level.

At the fourth stage T4, the input signal IN is at a high level, thesecond clock signal CK2 is at a high level, the first node N1 is at ahigh level, the third node N3 is at a high level, the fourth node N4 isat a low level, the second node N2 is at a low level, and the outputsignal OUT remains at a high level.

At the fifth stage T5, the input signal IN is at a low level, the secondclock signal CK2 is at a low level, the first node N1 is at a highlevel, the third node N3 is at a high level, the fourth node N4 is at alow level, the second node N2 is at a low level, and the output signalOUT remains at a high level.

At the sixth stage T6, the input signal IN is at a low level, the firstclock signal CK1 is at a low level, the second clock signal CK2 is at ahigh level, the first node N1 is at a low level, the fourth node N4 isat a low level, the first control signal A1 is at a high level, thesecond transistor M2 is off, and the third node N3 is at a high level.Since the eighth transistor M8 is on, the second node N2 becomes at ahigh level, the tenth transistor M10 and the eleventh transistor M11 areoff, and the output signal OUT remains at a high level.

At the seventh stage T7, the input signal IN is at a low level, and thefirst control signal A1 is at a low level. Within the first time periodX1, the first capacitor C1 is rapidly charged and thus pulls down thepotential of the first node N1 to the potential of the first low levelsignal V1 so that the potential of the first low level signal V1 is lessthan the potential of the first voltage signal Vgl, and the secondtransistor M2 is on, so the potential of the third node N3 is thepotential of the first low level signal V1. The fourth node N4 is at ahigh level, the second node N2 is at a high level, and the eleventhtransistor M11 is off. Since the potential of the third node N3 is lessthan the potential of the first voltage signal Vgl, the potential of thegate of the tenth transistor M10 is less than the potential of thesource of the tenth transistor M10, the tenth transistor M10 can rapidlyapproach a saturation state, the tenth transistor M10 is on, and theoutput signal OUT of the shift register substantially coincides with thefirst voltage signal Vgl, thereby avoiding the tailing phenomenon of theoutput signal.

FIG. 23 is a schematic diagram of the circuit structure of another shiftregister according to an embodiment of the present disclosure. As shownin FIG. 23 , the first control unit 01 includes a fourth transistor M4.The source of the fourth transistor M4 receives the input signal IN, thedrain of the fourth transistor M4 is connected to the first node N1, andthe gate of the fourth transistor M4 receives the first clock signalCK1. The second control unit 02 includes a fifth transistor M5, a sixthtransistor M6, a seventh transistor M7, an eighth transistor M8, a ninthtransistor M9, a third capacitor C3, and a fourth capacitor C4. Thesource of the fifth transistor M5 receives the first clock signal CK1,the drain of the fifth transistor M5 is connected to the fourth node N4,and the gate of the fifth transistor M5 is connected to the first nodeN1. The source of the sixth transistor M6 receives the second clocksignal CK2, the drain of the sixth transistor M6 is connected to thefifth node N5, and the gate of the sixth transistor M6 is connected tothe fourth node N4. The source of the seventh transistor M7 receives thefirst voltage signal Vgl, the drain of the seventh transistor M7 isconnected to the fourth node M4, and the gate of the seventh transistorM7 receives the first clock signal CK1. The source of the eighthtransistor M8 receives the second voltage signal Vgh, the drain of theeighth transistor M8 is connected to the second node N2, and the gate ofthe eighth transistor M8 is connected to the first node N1. The sourceof the ninth transistor M9 is connected to the fifth node N5, the drainof the ninth transistor M9 is connected to the second node N2, and thegate of the ninth transistor M9 receives the second clock signal CK2.The first plate of the third capacitor C3 is connected to the fourthnode N4, and the second plate of the third capacitor C3 is connected tothe fifth node N5. The first plate of the fourth capacitor C4 receivesthe second voltage signal Vgh, and the second plate of the fourthcapacitor C4 is connected to the second node N2. The third control unit03 includes a tenth transistor M10, an eleventh transistor M11, and afourth capacitor C4. The source of the tenth transistor M10 receives thefirst voltage signal Vgl, the drain of the tenth transistor M10 outputsthe output signal OUT, and the gate of the tenth transistor M10 isconnected to the third node N3. The source of the eleventh transistorM11 receives the second voltage signal Vgh, the drain of the eleventhtransistor M11 outputs the output signal OUT, and the gate of theeleventh transistor M11 is connected to the second node N2. The fourthcontrol unit 04 includes a first capacitor C1. The first plate of thefirst capacitor C1 is connected to the third node N3, and the secondplate of the first capacitor C1 receives the first control signal A1.The fourth control unit 04 includes a first transistor M1. The source ofthe first transistor M1 receives the first control signal A1, the drainof the first transistor M1 is connected to the second plate of the firstcapacitor C1, and the gate of the first transistor M1 receives thesecond control signal A2. In this embodiment, the first control signalA1 and the second control signal A2 are the same signal. Within thefirst time period, the first control signal A1 is a low level signal,and the second control signal A2 controls the first transistor M1 to beon. FIG. 24 is a timing diagram of the circuit structure shown in FIG.23 . The timing will be described in detail below with reference toFIGS. 23 and 24 .

At the first stage T1, the input signal IN is at a high level, the firstclock signal CK1 is at a low level, the second clock signal CK2 is at ahigh level, the fourth transistor M4 is on, the first node N1 is at ahigh level, the seventh transistor M7 is on, the fourth node N4 is at alow level, the first control signal A1 is at a high level, the thirdnode N3 remains at a low potential, the second node N2 is at a highlevel, the eleventh transistor M11 is off, and the fourth node N4remains at a low level.

At the second stage T2, the input signal IN is at a high level, thefirst clock signal CK1 is at a low level, the second clock signal CK2 isat a high level, the first node N1 is at a high level, the fourth nodeN4 is at a low level, the second transistor M2 is on, the third node N3is at a high level, the second node N2 is at a high level, and theoutput signal OUT remains at a low level.

At the third stage T3, the input signal IN is at a high level, thesecond clock signal CK2 is at a low level, the first node N1 is at ahigh level, the third node N3 is at a high level, the fourth node N4 isat a low level, the second node N2 is at a low level, the eleventhtransistor M11 is on, and the output signal OUT is at a high level.

At the fourth stage T4, the input signal IN is at a high level, thesecond clock signal CK2 is at a high level, the first node N1 is at ahigh level, the third node N3 is at a high level, the fourth node N4 isat a low level, the second node N2 is at a low level, and the outputsignal OUT remains at a high level.

At the fifth stage T5, the input signal IN is at a low level, the secondclock signal CK2 is at a low level, the first node N1 is at a highlevel, the third node N3 is at a high level, the fourth node N4 is at alow level, the second node N2 is at a low level, and the output signalOUT remains at a high level.

At the sixth stage T6, the input signal IN is at a low level, the firstclock signal CK1 is at a low level, the second clock signal CK2 is at ahigh level, the first node N1 is at a low level, the fourth node N4 isat a low level, the first control signal A1 is at a high level, thesecond transistor M2 is off, and the third node N3 is at a high level.Since the eighth transistor M8 is on, the second node N2 becomes at ahigh level, the tenth transistor M10 and the eleventh transistor M11 areoff, and the output signal OUT remains at a high level.

At the seventh stage T7, the input signal IN is at a low level, and thefirst control signal A1 is at a low level. Within the first time periodX1, the first capacitor C1 is rapidly charged and thus pulls down thepotential of the first node N1 to the potential of the first low levelsignal V1 so that the potential of the first low level signal V1 is lessthan the potential of the first voltage signal Vgl, and the secondtransistor M2 is on, so the potential of the third node N3 is thepotential of the first low level signal V1. The fourth node N4 is at ahigh level, the second node N2 is at a high level, and the eleventhtransistor M11 is off. Since the potential of the third node N3 is lessthan the potential of the first voltage signal Vgl, the potential of thegate of the tenth transistor M10 is less than the potential of thesource of the tenth transistor M10, the tenth transistor M10 can rapidlyapproach a saturation state, the tenth transistor M10 is on, and theoutput signal OUT of the shift register substantially coincides with thefirst voltage signal Vgl, thereby avoiding the tailing phenomenon of theoutput signal.

FIG. 25 is a schematic diagram of the circuit structure of another shiftregister according to an embodiment of the present disclosure. As shownin FIG. 25 , the first control unit 01 includes a fourth transistor M4.The source of the fourth transistor M4 receives the input signal IN, thedrain of the fourth transistor M4 is connected to the first node N1, andthe gate of the fourth transistor M4 receives the first clock signalCK1. The second control unit 02 includes a fifth transistor M5, a sixthtransistor M6, a seventh transistor M7, an eighth transistor M8, a ninthtransistor M9, a third capacitor C3, and a fourth capacitor C4. Thesource of the fifth transistor M5 receives the first clock signal CK1,the drain of the fifth transistor M5 is connected to the fourth node N4,and the gate of the fifth transistor M5 is connected to the first nodeN1. The source of the sixth transistor M6 receives the second clocksignal CK2, the drain of the sixth transistor M6 is connected to thefifth node N5, and the gate of the sixth transistor M6 is connected tothe fourth node N4. The source of the seventh transistor M7 receives thefirst voltage signal Vgl, the drain of the seventh transistor M7 isconnected to the fourth node M4, and the gate of the seventh transistorM7 receives the first clock signal CK1. The source of the eighthtransistor M8 receives the second voltage signal Vgh, the drain of theeighth transistor M8 is connected to the second node N2, and the gate ofthe eighth transistor M8 is connected to the first node N1. The sourceof the ninth transistor M9 is connected to the fifth node N5, the drainof the ninth transistor M9 is connected to the second node N2, and thegate of the ninth transistor M9 receives the second clock signal CK2.The first plate of the third capacitor C3 is connected to the fourthnode N4, and the second plate of the third capacitor C3 is connected tothe fifth node N5. The first plate of the fourth capacitor C4 receivesthe second voltage signal Vgh, and the second plate of the fourthcapacitor C4 is connected to the second node N2. The third control unit03 includes a tenth transistor M10, an eleventh transistor M11, and afourth capacitor C4. The source of the tenth transistor M10 receives thefirst voltage signal Vgl, the drain of the tenth transistor M10 outputsthe output signal OUT, and the gate of the tenth transistor M10 isconnected to the third node N3. The source of the eleventh transistorM11 receives the second voltage signal Vgh, the drain of the eleventhtransistor M11 outputs the output signal OUT, and the gate of theeleventh transistor M11 is connected to the second node N2. The fourthcontrol unit 04 includes a first capacitor C1, a first transistor M1, asecond capacitor C2, and a third transistor M3. The first plate of thefirst capacitor C1 is connected to the third node N3, and the secondplate of the first capacitor C1 is connected to the first control signalA1. The source of the first transistor M1 receives the first controlsignal A1, the drain of the first transistor M1 is connected to thesecond plate of the first capacitor C1, and the gate of the firsttransistor M1 receives the second control signal A2. The first plate ofthe second capacitor C2 is connected to the gate of the first transistorM1, and the second plate of the second capacitor C2 receives the secondvoltage signal Vgh. The gate of the first transistor M1 is connected tothe first node N1, that is, the second control signal A2 is a potentialsignal of the first node N1. The source of the third capacitor M3receives the second voltage signal Vgh, the drain of the thirdtransistor M3 is connected to the third node N3, and the gate of thethird transistor M3 is connected to the second node N2. In thisembodiment, the first clock signal CK1 and the first control signal A1are the same signal. Within the first time period X1, the first controlsignal A1 is a low level signal, the second control signal A2 controlsthe first transistor M1 to be on, and the second node N2 controls thethird transistor M3 to be off. For the timing of the circuit structureshown in FIG. 25 , reference may be made to the description OF FIG. 18 .Compared with the solutions shown in FIGS. 17 and 18 , in thisembodiment of the present disclosure, the potential of the second nodeN2 may be used to control the potential of the third node to ensure thesignal stability when the third node N3 is at the high level. Since eachclock signal is subjected to multiple transitions, the potential of thefirst node N1 and the potential of the third node N3 may float in thetransition process. In this embodiment of the present disclosure, thethird transistor M3 is provided, and when the second node N2 is at a lowlevel, the third transistor M3 is on to control the third node N3 to bestabilized at a high level. Before the second node N2 becomes at a highlevel, the third transistor M3 is off so that the potential of the thirdnode N3 does not change, and only when the second node N2 becomes at ahigh level does the potential of the third node N3 become a potentiallower than the potential of the first voltage signal Vgl, therebyreducing the tailing phenomenon.

In an embodiment, the first control signal and the first clock signalare pulse signals of different timing, and the first control signal andthe second clock signal are pulse signals of different timing, whereactive pulses of the first clock signal, the first control signal, andthe second clock signal are sequentially generated. For the abovedescription, for example, a reference may be made to FIGS. 20, 22, and24 .

In an embodiment, the duration of the active pulse of the first clocksignal is less than or equal to the duration of the active pulse of thesecond clock signal, and the duration of the active pulse of the firstcontrol signal is less than or equal to the duration of the active pulseof the second clock signal. For the above description, for example, areference may be made to FIGS. 20, 22, and 24 .

In an embodiment, the duration of the active pulse of the first controlsignal is less than or equal to the duration of the active pulse of thefirst clock signal. Since the first clock signal needs to participate inthe driving process of the first control unit, the second control unit,and the third control unit, and the first control signal only needs tocontrol the fourth control unit. Therefore, the duration of the activepulse of the first control signal may be set to be less than or equal tothe duration of the active pulse of the first clock signal to save theduration of the active pulse and save the power consumption.

In an embodiment, the sum of the duration of the active pulse of thefirst clock signal and the duration of the active pulse of the firstcontrol signal is equal to or greater than the duration of the activepulse of the second clock signal. The first clock signal and the firstcontrol signal control the potential change of both the first node andthe third node N3 together, and the second clock signal controls thepotential change of the second node N2. In some implementations of thepresent disclosure, the sum of the active pulses of the first clocksignal and the first control signal may be set equal to the active pulseof the second clock signal. In order to ensure the potential of thethird node N3 is pulled down within at least the first time period inwhich the first node is at a low potential, the duration of the activepulse of the first control signal may be appropriately increased toensure that the output signal of the shift register is free of tailing.

In an embodiment, the active pulse of the first clock signal at leastpartially overlaps the active pulse of the first control signal. Theactive pulse of the first clock signal may at least partially overlapthe active pulse of the first control signal so that the active pulse ofthe first clock signal and the active pulse of the first control signalcan be appropriately increased to ensure stable control of thepotentials of the first node and the third node under the premise thatthe driving period is unchanged.

In an embodiment, the on time of the active pulse of the first clocksignal is earlier than the on time of the active pulse of the firstcontrol signal, and the end time of the active pulse of the first clocksignal is earlier than or equal to the end time of the active pulse ofthe first control signal. Since the potential of the first node N1 needsto continue to be pulled down by the fourth control unit after the firstnode N1 changes from a high level to a low level, the on time of theactive pulse of the first clock signal needs to be earlier than the ontime of the active pulse of the first control signal. In this embodimentof the present disclosure, the end time of the active pulse of the firstclock signal is set to be earlier than or synchronize the end time ofthe active pulse of the first control signal so that it is ensured thatthe fourth control unit continues to control the potential of the thirdnode N3 to be pulled down within at least the first period in which thepotential of the first node is at a low level. If the end time of theactive pulse of the first clock signal is later than the end time of theactive pulse of the first control signal, the potential of the thirdnode may change back to the potential before the first node potential isnot pulled down.

In an embodiment, the active pulse of the first control signal may alsobe set to have no overlap with the active pulse of the first clocksignal according to the demands of the actual product, as shown in FIGS.20, 22, and 24 .

In an embodiment, during a complete process of an inactive pulse shiftfrom the input signal to the output signal, the on time of an inactivepulse of the input signal is first interval earlier than the on time ofthe active pulse of the first clock signal, and the on time of theactive pulse of the first clock signal is second interval earlier thanthe on time of the active pulse of the first control signal, where thefirst interval is equal to the second interval. For example, withreference to FIG. 20 , the inactive pulse of the input signal IN is at ahigh level, and the on time of the inactive pulse of the input signal INis earlier than the on time of the active pulse (low level) of the firstclock signal CK1 by first interval tl. The on time of the active pulse(low level) of the first clock signal CK1 is earlier than the on time ofthe active pulse of the first control signal A1 by the second intervalt2. With the addition of the control of the first control signal A1, theoutput signal OUT changes from the high level to the low level at the ontime of the active pulse of the first control signal A1, and the fallingedge of the output signal OUT is delayed by the second interval t2 isthe difference between the on time of the active pulse (low level) ofthe first clock signal CK1 and the on time of the active pulse of thefirst control signal A1.

Therefore, the rising edge of the input signal IN is earlier than thefalling edge of the first clock signal CK1 by the first time interval t1which is equal to the second time interval t2, so as to ensure that theinactive pulse widths of the input signal IN and the output signal OUTare equal to each other and their waveforms are also consistent witheach other.

In an embodiment, the second clock signal outputs an inactive pulsewithin the first time period. For example, with reference to FIG. 20 ,in this embodiment of the present disclosure, within the first timeperiod X1 before the second clock signal CK2 outputs the active pulse(low level), the third node N3 is rapidly pulled down to a potentiallower than that of the first voltage signal Vgl so that the tailingphenomenon is eliminated as much as possible.

In an embodiment, the time period for receiving the low-level signal bythe first node further includes a second time period X2, and thepotential of the third node is the first low level signal within thefirst time period X1 and the potential of the third node is a high levelsignal within the second time period X2. For example, with reference toFIGS. 20, 22, and 24 , within the second time period X2, the first clocksignal CK1 is at a low level, and when the first control signal is at ahigh level, the third node N3 remains a high level signal. Within thefirst time period X1 after the first control signal A1 becomes at a lowlevel, the third node N3 is pulled down to a potential lower than thepotential of the first voltage signal Vgl so that the tailing phenomenonis eliminated as much as possible.

Based on the same concept described above, an embodiment of the presentdisclosure further provides a display device. The display deviceincludes the display panel described in any embodiment of the presentdisclosure. Therefore, the display device provided by this embodiment ofthe present disclosure has the corresponding beneficial effects of thedisplay panel provided by the embodiments of the present disclosure,which is not repeated here. Exemplarily, the display device may be amobile phone, a computer, a smart wearable device (for example, asmartwatch), an onboard display device, and other electronic devices,which is not limited in the embodiments of the present disclosure.Exemplarily, FIG. 26 is a structural diagram of a display deviceaccording to an embodiment of the present disclosure. As shown in FIG.26 , the display device includes the display panel 100 in theembodiments described above.

It is to be noted that the preceding are only preferred embodiments ofthe present disclosure and the technical principles used therein. It isto be understood by those skilled in the art that the present disclosureis not limited to the embodiments described herein. Those skilled in theart can make various apparent modifications, adaptations, andsubstitutions without departing from the scope of the presentdisclosure. Therefore, while the present disclosure has been describedin detail via the preceding embodiments, the present disclosure is notlimited to the preceding embodiments and may include equivalentembodiments without departing from the concept of the presentdisclosure. The scope of the present disclosure is determined by thescope of the appended claims.

What is claimed is:
 1. A display panel, comprising: a driver circuitcomprising a shift register that is N-stage cascaded, wherein N is anumber greater than or equal to 2; wherein the shift register comprises:a third control unit configured to receive a first voltage signal andgenerate an output signal in response to a signal of a third node, orreceive a second voltage signal and generate an output signal inresponse to a signal of a second node, wherein the first voltage signalis a low level signal, and the second voltage signal is a high levelsignal; and a fourth control unit comprising a first capacitor, a firsttransistor and a second transistor, wherein a second plate of the firstcapacitor is connected to a drain of the first transistor, a source ofthe second transistor is connected to a first node, and a drain of thesecond transistor is connected to the third node, wherein a gate of thefirst transistor receives a second control signal, and the secondcontrol signal is a signal of the first node.
 2. The display panel ofclaim 1, wherein both a first plate of the first capacitor and the gateof the first transistor are connected to the first node.
 3. The displaypanel of claim 1, wherein the gate of the second transistor receives afirst control signal.
 4. The display panel of claim 3, wherein the firstcontrol signal is a same signal as the second control signal.
 5. Thedisplay panel of claim 1, wherein a source of the first transistorreceives a first control signal.
 6. The display panel of claim 5,wherein the shift register comprises a first control unit configured toreceive an input signal and control a signal of a first node in responseto a first clock signal.
 7. The display panel of claim 6, wherein thefirst control signal and the first clock signal are pulse signals havingdifferent timing.
 8. The display panel of claim 6, wherein the displaypanel comprises: an active pulse of the first control signal at leastpartially overlaps an active pulse of the first clock signal; or anactive pulse of the first control signal has no overlap with an activepulse of the first clock signal.
 9. The display panel of claim 6,wherein the first control signal is a same signal as the first clocksignal.
 10. The display panel of claim 6, wherein during at least afirst time period when a potential of the first node is a low levelsignal, the first transistor is turned on.
 11. The display panel ofclaim 10, wherein during the first time period, the first control signalis a low level signal.
 12. The display panel of claim 10, wherein duringthe first time period, the second transistor is turned on.
 13. Thedisplay panel of claim 6, wherein the shift register comprises: a secondcontrol unit configured to receive a first voltage signal and a secondvoltage signal and control the signal of the second node in response tothe signal of the first node, the first clock signal, and a second clocksignal.
 14. The display panel of claim 13, wherein a sum of a durationof an active pulse of the first clock signal and a duration of an activepulse of the first control signal is equal to or greater than a durationof an active pulse of the second clock signal.
 15. The display panel ofclaim 1, wherein the fourth control unit further includes a secondcapacitor, a first plate of the second capacitor is connected to thegate of the first transistor, and a second plate of the second capacitorreceives the second voltage signal.
 16. The display panel of claim 15,wherein a capacitance value of the first capacitor is smaller than acapacitance value of the second capacitor.
 17. The display panel ofclaim 13, wherein the first control unit comprises: a fourth transistor,a source of the fourth transistor receives the input signal, a drain ofthe fourth transistor is connected to the first node, and a gate of thefourth transistor receives the first clock signal; the second controlunit comprises: a fifth transistor, a source of the fifth transistorreceives the first clock signal, a drain of the fifth transistor isconnected to a fourth node, and a gate of the fifth transistor isconnected to the first node; a sixth transistor, a source of the sixthtransistor receives the second clock signal, a drain of the sixthtransistor is connected to a fifth node, and a gate of the sixthtransistor is connected to the fourth node; a seventh transistor, asource of the seventh transistor receives the first voltage signal, adrain of the seventh transistor is connected to the fourth node, and agate of the seventh transistor receives the first clock signal; aneighth transistor, a source of the eighth transistor receives the secondvoltage signal, a drain of the eighth transistor is connected to thesecond node, and a gate of the eighth transistor is connected to thefirst node; a ninth transistor, a source of the ninth transistor isconnected to the fifth node, a drain of the ninth transistor isconnected to the second node, and a gate of the ninth transistorreceives the second clock signal; a third capacitor, a first plate ofthe third capacitor is connected to the fourth node, and a second plateof the third capacitor is connected to the fifth node; a fourthcapacitor, a first plate of the fourth capacitor receives the secondvoltage signal, and a second plate of the fourth capacitor is connectedto the second node; the third control unit comprises: a tenthtransistor, a source of the tenth transistor receives the first voltagesignal, a drain of the tenth transistor outputs an output signal, and agate of the tenth transistor is connected to the third node; an eleventhtransistor, a source of the eleventh transistor receives the secondvoltage signal, a drain of the eleventh transistor outputs an outputsignal, and a gate of the eleventh transistor is connected to the secondnode.
 18. A display device, comprising a display panel, wherein thedisplay panel comprises: a driver circuit comprising a shift registerthat is N-stage cascaded, wherein N is a number greater than or equal to2; wherein the shift register comprises: a third control unit configuredto receive a first voltage signal and generate an output signal inresponse to a signal of a third node, or receive a second voltage signaland generate an output signal in response to a signal of a second node,wherein the first voltage signal is a low level signal, and the secondvoltage signal is a high level signal; and a fourth control unitcomprising a first capacitor, a first transistor and a secondtransistor, wherein a second plate of the first capacitor is connectedto a drain of the first transistor, a source of the second transistor isconnected to a first node, and a drain of the second transistor isconnected to the third node, wherein a gate of the first transistorreceives a second control signal, and the second control signal is asignal of the first node.